than in unaffected relatives or controls. Based on the trio and quartet approach, consisting of patient, parents, and unaffected sibling, the most frequently mutated genes identified so far include CDH8, SCN2A, DYRK1A, and CTNNB1 [O’Roak et al., 2012a; Krumm et al., 2014]. Many genes implicated in autism were previously identified as causative for ID, epilepsy, schizophrenia or bipolar disorder, suggesting an overlap in the underlying etiology of neurodevelopmental disorders.
